The present invention relates to a device for intracorporal, minimal-invasive treatment of a patient, comprising a working instrument that can be introduced into a body cavity of the patient for carrying out a treatment step, wherein a distal end of the introduced working instrument defines an intracorporal working area, and at least one image pick-up unit for picking up an image of the intracorporal working area, further comprising positioning means for orienting an optical axis of the image pick-up unit in dependency on a spatial position of the intracorporal working area, wherein the positioning means comprise a guide shaft, in which the working instrument is guided, and wherein the image pick-up unit is pivotably fixed at an intracorporal portion of the guide shaft.
Such a device is known from U.S. Pat. No. 5,166,787.
In the minimal-invasive, surgical treatment of patients, working instruments are brought to the location to be treated in the body of the patient merely through one or several small incisions. The visual control of the working steps to be carried out in the body of the patient is done endoscopically. An example for a minimal-invasive standard operation is the laparoscopical colecystectomy. In this procedure, three small openings are cut into the abdominal area of the patient. One of the openings serves for introducing an endoscope with a video camera, the image of which can be seen on a monitor by the treating physician. Working instruments, like e.g. scissors, forceps or the like, are introduced through the other two openings.
When the operation is carried out, the endoscope is, today, usually handled by an assistant physician, who tracks the endoscope to changes and displacements of the working area so far that the treating physician always has the working instruments in his visual field. Such camera assistance requires, however, a very good coordination between the treating physician and the assistant physician, what often is problematic in practice. Moreover, the necessary camera assistance requires more staff in carrying out the operation, which has a negative effect on the costs.
In DE 195 29 950 C1, a device was, thus, suggested, in which the camera assistant is replaced by an automatically controlled robot that is arranged outside the body of the patient. For the control of the robot, the image picked up by the endoscope camera is evaluated with reference to the position of working instrument or instruments appearing in the image picked up. The working instruments are marked with colors to this end, so that they can be identified by means of the proposed image treatment algorithm.
It is true that such a robot control can generally replace the assistant physician required as in the past, it is, however, expensive from the technical point of view and has, moreover, further disadvantages. In particular, the robot system requires a very large mechanical holder, which takes a relatively large space over the patient. This limits the freedom of movement for the treating physician over the patient. Apart from that, the sterilization of the relatively large robot device is difficult. The assembly and disassembly of such a device also requires relatively much time, what has a negative effect on the costs and the efficiency particularly in standard operations.
From U.S. Pat. No. 5,166,787 mentioned at the outset, an endoscope with a video camera arranged on its distal end is known, wherein the video camera is movable as a whole with respect to the distal end of the endoscope shaft after being introduced into the body cavity to be examined of the patient. The video camera can be pivoted about an axis running parallel with respect to the longitudinal axis of the shaft, which forms a body-own axis of the video camera, in a plane transverse to the longitudinal direction of the shaft out of the longitudinal axis of the shaft. The viewing direction of the video camera remains, in this procedure, in every pivot position of the video camera parallel with respect to the longitudinal center axis of the shaft. In another embodiment, the video camera is additionally pivotable, about a pivot axis running transversely with respect to the longitudinal direction of the shaft, again, about a video camera-own axis. In this procedure, the viewing angle of the video camera is changed with respect to the longitudinal axis of the shaft, however, only such viewing directions are created, which form a very acute angle with the longitudinal axis of the shaft, or such viewing directions, which are facing away from the longitudinal center axis of the shaft and are, thus, not useful for the endoscope when used in an operation. In other words, it is not possible to reach the same or at least similar perspective observation conditions with this known endoscope as with an endoscope that was introduced into the body cavity via an additional access.
Neither the known endoscope nor the video camera, moreover, have positioning means by which the viewing direction and/or the image field of the video camera can automatically be tracked to certain displacements or shiftings of the intracorporal working area. Thus, also for this known device a manual positioning with the disadvantages already mentioned is necessary.
It is, thus, an object of the present invention to provide a device of the type mentioned at the outset, by which at least similar perspective viewing conditions can be reached like with an endoscope that is introduced into the body cavity via an additional access.
According to the invention, the object underlying the invention is achieved by a device for intracorporal, minimal-invasive treatment of a patient, comprising:
a working instrument that can be introduced into a body cavity of said patient for carrying out a treatment step, said working instrument having a distal end defining an intracorporal working area when said working instrument is introduced in said body cavity;
at least one image pick-up unit for picking up an image of said intracorporal working area, said image pick-up unit having an optical axis; and
positioning means for orienting said optical axis of said image pick-up unit in dependency on a spatial position of said intracorporal working area, said positioning means further comprising:
a guide shaft in which said working instrument is guided, said guide shaft having an intracorporal portion, and
a holder pivotably fixed to said intracorporal portion of said guide shaft, wherein said image pick-up unit is arranged at said holder in a distance from a location where said holder is linked to said guide shaft, such that said image pick-up unit is intracorporally pivotable into a working position, in which said optical axis runs angularly to a longitudinal center axis of said guide shaft and points to said longitudinal center axis.
The device according to the invention differs from the known device in particular by the fact that the image pick-up unit is fixed at the guide shaft via a holder, and, due to the pivotability of the holder, can be pivoted away from the guide shaft, i.e. can be spaced apart from the guide shaft. In that way, the viewing direction can be positioned under a larger angle with respect to the longitudinal axis of the guide shaft, which corresponds to the perspective viewing conditions of an endoscope being introduced through an additional opening into the body cavity, what is welcomed by the physician. By the coupling of the image pick-up unit with the intracorporal portion of the guide shaft, it is moreover possible, as is in the following described in more detail, that the image pick-up unit can automatically follow at least a part of the movements of the working instrument, without a robot or a corresponding device outside of the body cavity being necessary. It is therefore practically a seeing working instrument. The device according to the invention is consequently considerably smaller and more space saving and less cost-expensive than common devices with an extracorporal positioning device.
By means of the present invention, practically a xe2x80x9cdistal end of an endoscopexe2x80x9d is coupled with the working instrument, which can be positioned with a perspective viewing direction onto the working area, just as if a whole endoscope was introduced into the body cavity through an additional opening.
In preferred embodiments of the invention, which are described in more detail in the following, a separate holder for the image pick-up unit outside the body cavity of the patient can even be completely omitted, so that in this case no additional space at all over the patient is necessary. The freedom of movement for the treating physician is then not limited at all anymore.
In addition, with the smaller device the effort for assembly and disassembly is reduced, what has a positive effect on the efficiency and the handling in practical use.
Finally, the sterilization of the device according to the invention is easier due to the smaller dimensions. In spite of all that, the device of the invention has all advantages of an automatic tracking system, so that, altogether, a considerable cost saving in minimal-invasive treatments of patients is possible. Apart from that, the risk of an unintended contamination of the image pick-up unit by tissue contact is reduced. Furthermore, also shorter operation times can be reached due to the improved handling, what results in less strain and a lesser operation risk for the patient.
In minimal-invasive operations, as already mentioned at the outset, two incisions are created, wherein an active working element, e.g. scissors is introduced, through the first incision, from the sight of the physician usually the xe2x80x9crightxe2x80x9d one, and, a passive or more passive working instrument, e.g. a holding instrument, is introduced through the other one, i.e. from the sight of the physician the xe2x80x9cleftxe2x80x9d one. For the device according to the invention, it is particularly preferred in this sense, if the image pick-up unit is coupled with the more passive working instrument via the guide shaft.
The object mentioned before is therefore completely achieved.
In a preferred embodiment, the holder has at least one pivot arm that is articulatedly fixed to the intracorporal portion.
By this measure, the device with the functions and effects according to the invention mentioned before can be configured particularly simple in design in order to configure a coupling of the image pick-up unit on the guide shaft for obtaining perspective viewing conditions.
In a particularly simple preferred embodiment, the image pick-up unit is arranged at the free end of the at least one pivot arm in such a way that the optical axis of the image pick-up unit runs approximately perpendicular to the longitudinal axis of the pivot arm and points to the longitudinal center axis of the guide shaft.
In this embodiment, only one articulation is necessary in an advantageous manner, namely the one via which the at least one pivot arm is connected to the guide shaft and via which the image pick-up unit can then be pivoted out from the guide shaft for adjusting a perspective viewing angle, in order to adjust the desired perspective angle between the longitudinal axis of the guide shaft or the working instrument and the image pick-up unit.
In such a simple embodiment of the device according to the invention, it is advantageous to integrate even more than one image pick-up unit in order to obtain a video stereo system for an improved stereoscopic representation and reproduction.
In the embodiment mentioned before, it is further preferred if the pivot arm has an adjustable length.
This measure has the advantage that in a displacement of the working instrument in axial direction the angle between the optical axis and the image pick-up unit and the longitudinal axis of the working instrument can be held constant by shortening or extending the pivot arm in the one-axis embodiment of the articulation mechanism. The pivot arm can be designed in a telescope-like manner to this end, for example.
In another preferred embodiment of the invention, the holder has a one-axis or a multi-axis articulation mechanism.
This measure has the advantage that with increasing number of the axes of the articulation mechanism the number of degrees of freedom of movement of the image pick-up unit increases with reference to the guide shaft. As a result, the image pick-up unit can be oriented onto the working area, if a multi-axis articulation mechanism is used.
In another preferred embodiment, the image pick-up unit is pivotable into a resting position at the guide shaft, in which an outer cross-sectional contour of the image pick-up unit is arranged in an essentially congruent manner with respect to an outer cross-sectional contour of the guide shaft.
This measure has the advantage that the image pick-up unit can be introduced together with the guide shaft, i.e. through the same opening, into the body cavity of the patient. As a result, e.g. in laparoscopical colecystectomy, one of the three incisions required up to now can be dispensed with. This results in a lesser traumatization of the patient, what results, again, in a lesser risk. In other applications, e.g. in tube sterilization, even only one incision is required with the perspectively seeing instrument of the invention.
In another embodiment of the invention, the image pick-up unit is fixable via an intracorporally activatable coupling mechanism at the guide shaft.
In this embodiment of the invention, the initially separate image pick-up unit can be intracorporally fixed at the guide shaft. By this measure, it is possible to introduce the image pick-up unit separately from the guide shaft into the body cavity of the patient, e.g. over an own incision opening. The measure has the advantage that both the image pick-up unit and the guide shaft each for itself can be realized in a larger dimension, so that altogether there is more construction space available. This is particularly advantageous in view of the image pick-up unit, since a larger construction space can, for example, receive more optical fibers and, thus, allows a higher light intensity.
In another embodiment of the invention, the positioning means comprise a mechanically constrained coupling between the working instrument and the image pick-up unit.
A mechanically constrained coupling allows in a simple way an automatic tracking of the image pick-up unit, without additional actuating drives or sensors being necessary. As a result, this embodiment of the invention can be realized with very low costs and, moreover, in a very robust manner. The latter is particularly advantageous for the practical use in working and in sterilizing.
In this connection, it is preferred if the positioning means have locking means for an at least partial axial immobilization of the working instrument with respect to the guide shaft.
This measure represents the simplest tracking between the image pick-up system and the working area, as the image pick-up unit connected with the guide shaft via the holder, by the axial fixation of the working instrument with respect to the guide shaft, is entrained by every axial movement of the working instrument. The pivoted position of the holder is maintained in the simplest case, so that also the perspective viewing direction remains unchanged. The perspective observation angle can, before, be fixed by pivoting the holder and, thus, the image pick-up unit, such that the point of the working instrument which defines the working area rests approximately in the image center. The working instrument is then immobilized e.g. at the proximal side at the guide shaft by means of the locking means, such that it is preferably rotationally movable in the guide shaft, but can, however, be axially moved only in connection with the guide shaft. In order to achieve a complete axial fixation of the working instrument at the guide shaft, in the simplest case, an annular groove can be provided in the guide shaft in which runs a pin which is preferably spring-loaded and which is located at the working instrument. By such a locking, it is guaranteed that the working area lies in the viewing area of the image pick-up unit in spite of a movement of the working instrument.
In this connection, it is further preferred if the locking means are configured in such a way that the working instrument is axially freely displaceable with respect to the guide shaft within predetermined limits, but axially entrains the guide shaft, if the working instrument is displaced beyond the predetermined axial limits.
It may be interfering when the image pick-up unit always follows the working instrument when it is axially moved, so that no visual registration of the movement of the instrument is possible. By the embodiment described before, it is now possible to move the instrument axially with respect to the guide shaft within predetermined limits, without the guide shaft and, with it, the image pick-up unit being also moved. The limits mentioned before are preferably adjusted in such a way that they just correspond to the distance between the entering of the point of the working instrument into the image field and the outgoing of the point of the working instrument from the image field. Only if the point of the working instrument would leave the image field, the locking means become active and entrain, then, the guide shaft and, with it, the image pick-up unit. Such locking means may be realized by a broader annular groove in the guide shaft, in which runs a pin arranged at the working instrument which is axially shorter compared to the axial length of the annular groove.
In comparison to the very simple tracking mentioned before, it is also preferred if the working instrument is axially freely displaceable with respect to the guide shaft, and that the holder has coupling means, which can be brought in engagement with the working instrument in such a way that, when the working instrument is displaced relative to the guide shaft, the holder is pivoted, in order to track the optical axis to the working area.
In this embodiment, thus, an axial relative displacement between the working instrument and the guide shaft results in a pivoting of the holder at the guide shaft and, thus, in a change of the viewing direction of the image pick-up unit, wherein the coupling causes the viewing direction of the image pick-up unit to be always directed onto the working area.
In a further embodiment of the invention, the positioning means comprise an actuator unit for pivoting the image pick-up unit and a sensor unit coupled therewith, by which a current position of the working area can be determined.
This measure may be used alternatively to a mechanically constrained coupling. The measure is, however, preferably used complementary to a mechanically constrained coupling, wherein the mechanically constrained coupling on the one hand and the sensor/actuator unit on the other hand control different degrees of freedom of movement of the image pick-up unit. The measure has the advantage that a sensor/actuator unit allows an electronic positioning, which results in a higher flexibility and a larger scope of arrangements. This holds true both for the design of the device according to the invention and for its practical use.
In a further embodiment of the measure mentioned before, the sensor unit comprises measuring means for determining a relative position of the working instrument with reference to the guide shaft.
The measuring means may e.g. comprise a bar code, a resistance measurement, an angle decoder or a position sensor on the basis of infrared, ultrasound or electromagnetic fields. The measure has the advantage that such position sensors are sufficiently known per se in the prior art, so that a position determination by a position sensor is very simply possible. The reference to the guide shaft allows, moreover, a reference that is always constant and exactly known.
In a further embodiment, which can be used both alternatively and complementary to the measure mentioned before, the sensor unit comprises image-processing means for identification of the distal end of the working instrument in the image picked up.
This measure has the advantage that additional measuring devices, like e.g. in the form of a position sensor, can be dispensed with, whereby the necessary construction space can also be saved. Complementary to a position sensor, a redundancy is achieved which allows an increase of the reliability and measuring accuracy.
Preferably, in the working position, the optical axis encloses an angle of at least 10xc2x0, particularly preferably between 20xc2x0 and 700xc2x0, with the longitudinal center axis of the guide shaft.
Also preferably, in the working position, the image-entering opening of the image pick-up unit is in a lateral distance from the guide shaft, which is larger than approximately 1 cm.
Due to these measures, the operating physician achieves an optimal viewing angle onto the working area, what considerably facilitates the carrying out of the operation. From an angle of about 10xc2x0, the operating physician achieves a sufficient lateral view (perspective) on the distal end of the working instrument. The angle range between 20xc2x0 and 70xc2x0 is optimal. The measure is particularly advantageous if the image pick-up unit is introduced via the same incision into the body cavity of the patient as the guide shaft, as the operating physician would otherwise have to accept disadvantages with respect to the viewing angle in this case.
In a further embodiment of the invention, the image pick-up unit is an integrated video probe, which provides an electrical image signal of the working area.
Preferably, the video probe is a stereo video probe, which allows for the operating physician an, again, better perspective stereoscopic image, in particular in connection with the embodiment according to claim 3. The measure has generally the advantage that an electric image signal, in particular in digital form, can be transported without or with relatively slight quality losses, because no illustration errors like in lens systems occur. As a result, the quality of the image reproduction is very high in this measure. Just for stereo image pick-up units, the invention has the additional advantage that double images and/or distortion are reduced, as an always constant, optimal working distance and, thus, a constant 3D perspective are maintained.
In connection with the measure mentioned before, it is preferred if the image picked up by the image pick-up unit is telemetrically transmitted.
It is advantageous herewith that the image picked up by the video sensor can be transmitted into the proximal direction without expensive cable systems. In connection with the one-axis or multi-axis articulation mechanism mentioned before for coupling the image pick-up unit onto the guide shaft, this is particularly advantageous, because no cables have to be led through the articulation or the articulations of the pivot mechanism. Also the susceptibility for damages and an untightness due to the implementation of cables is considerably reduced by the measure mentioned before.
It is further preferred if the image pick-up unit has a transmitter, the transmitted image signals of which are received by a receiver.
The integration of a transmitter into the image pick-up unit, i.e. into the video sensor, has the advantage that cables for image transmission between the video sensor and the receiver can be completely dispensed with, so that the image pick-up unit can be completely encapsulated, wherein problems of tightness can be completely removed.
It is further preferred if the receiver or at least its antenna is arranged at the intracorporal portion of the guide shaft.
While it is also possible to do the telemetric transmission from the image pick-up unit through the abdominal wall to an extracorporally arranged receiver, the measure mentioned before has the advantage that also frequency ranges of higher frequency can be used, which, otherwise, would be dampened by the abdominal wall.
In a further preferred embodiment, an illuminating device is arranged at the image pick-up unit, which has preferably at least one light emitting diode.
This has the advantage that also for a light supply to the working area, optical fibers can be completely dispensed with, which cannot be led over the articulation mechanism and, thus, would have to be led through the guide shaft. A light emitting diode at the image pick-up unit has, however, the essential advantage that the direction of the illumination and the viewing direction of the image pick-up is the same, so that, when the image pick-up unit is tracked to a movement of the working instrument, also the illumination is optimally tracked.
In a further preferred embodiment, the image pick-up unit has a source of energy, e.g. a battery or an accumulator, for its supply.
Altogether, thus, a completely autonomous image pickup unit is created, if necessary, with a light source for illuminating the working area, the image pick-up unit being advantageous in connection with the positionability of the image pick-up unit according to the invention.
Taking CMOS video sensors as a basis, it is possible in the future that such autonomous image pick-up units can be manufactured as one-way products, so that problems of cleaning and recycling will not arise any more.
In an alternative embodiment of the measure mentioned before, the image pick-up unit is an optical element, which provides an optical image signal of the working area.
The optical element can be, for example, an ordered fiber bundle, a lens system and/or a mirror system. The measure has the advantage that such passive elements can be realized in very small dimensions and with usual, controllable techniques. This is particularly advantageous if the image pick-up unit is to be introduced via the same opening into the body cavity of the patient as the guide shaft.
In a further embodiment of the invention, the guide shaft has a guide channel that is open on both ends for receiving and guiding exchangeable working instruments.
This measure allows the operating physician to use different working instruments in the same guide shaft, wherein the image pick-up unit can always be constantly directed onto the defined working area. As a result, the operating physician can orient very quickly and simply even if the working instrument is changed. Alternatively to this measure, however, it is also possible to couple the different working instruments each with an own guide shaft.
As already mentioned before, according to embodiments mentioned before, the working instrument is guided in the guide shaft movably in axial direction.
This measure has the advantage that the operating physician can manipulate the working instrument in the working area as usual and, in doing so, can perform e.g. cuts with scissors in the usual way.
In a further embodiment, the working instrument is immovable in radial direction in the guide shaft.
This measure has the advantage that the guide shaft directly follows radial movements of the working instrument, which is a particularly simple and effective constrained coupling. When the working instrument rotates in the guide shaft, the guide shaft is preferably not entrained, so that the viewing direction of the image pick-up unit remains unchanged, as is provided in another preferred embodiment.
In comparison to a complete radial fixation, it can, however, be advantageous, again, if the working instrument has a certain radial play with respect to the guide shaft, so that, in a lateral movement of the working instrument transverse with respect to the longitudinal axis of the working instrument, the image pick-up unit is not entrained within certain limits and the image field remains unchanged, and an entrainment occurs only if the movement exceeds the limits, as it was described before for the axial mobility.
In a further embodiment of the invention, the image pick-up unit has means for modification of a picked up image sector.
In particular, the image pick-up unit of this embodiment has a zoom objective, by which the image of the working area can be enlarged within predetermined limits, without changing the spatial distance between the image pick-up unit and the working area. In that way, the operating physician obtains a further possibility to adjust a visual range that is optimal for the performance of the treatment, to be more precise, without having to change the position of the working instrument.
In a further embodiment of the invention, an illuminating device is arranged on the intracorporal portion of the guide shaft.
This measure has also the advantage that the working area is well illuminated. In combination with the measure mentioned before, due to the different illumination directions, different shadows are created, which cause an increase of the depth indentation or of the stereo effect.
It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.